Multilayer Filter Element With Coupled Coils for Wider Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filter elements with coils and capacitors in multilayer bodies have insufficient attenuation and bandwidth, limiting their effectiveness as low-pass filters.
Innovation Solution
A filter element design featuring a multilayer body with overlapping coils for magnetic coupling, differential connection of coils, and parallel connection of coils with capacitors to create multiple attenuation poles, enhancing attenuation and bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single capacitor is connected with coils in a multilayer body, then the filter element functions as a low pass filter, but the attenuation and bandwidth are insufficient
Solution Approach 1:
The filter circuit is segmented into multiple functional units: first and second coils with differential connection, first and second capacitors connected at different locations. This segmentation creates multiple attenuation poles (first attenuation pole from mutual inductance M and first capacitor, second attenuation pole from parallel connection of series circuit and second capacitor), thereby improving attenuation performance and bandwidth without excessive complexity
Solution Approach 2:
The patent utilizes the laminated direction (vertical dimension) of the multilayer body to arrange components on different layers. The first capacitor is connected between the node and reference potential electrode on one layer, while the second capacitor is connected in parallel to the series circuit on another layer. This dimensional arrangement enables multiple attenuation mechanisms without increasing planar footprint, resolving the contradiction between performance and complexity
2Reliability
If coils are arranged in laminated direction with magnetic coupling, then mutual inductance creates attenuation pole, but the attenuation band width remains insufficient
Solution Approach 1:
The patent exploits the vertical dimension (laminated direction) of the multilayer structure to place the first and second capacitors on different layers rather than spreading them out in the planar direction. The first capacitor connects the coil node to reference potential on one layer, while the second capacitor provides parallel connection on another layer. This vertical stacking achieves wide attenuation bandwidth while maintaining a compact footprint area
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves a wide attenuation band with steep passband-cutoff boundaries and effective reduction of eddy currents, resulting in improved frequency characteristics and attenuation performance.
Implementation Method 1
a coil opening of the first coil is overlapped with that of the second coil for magnetic coupling
Implementation Method 2
mutual inductance M occurring on a path from the node between the primary coil and the secondary coil
Implementation Method 3
The first capacitor and the second capacitor are provided in the laminated direction on layers different from layers of the multilayer body on which the first coil and the second coil are provided
Data Source
AI summary
First and second coils have winding axes in a laminated direction of base material layers and are magnetically coupled to each other. First and second capacitors are positioned in the laminated direction on layers different from layers on which the first and second coils are provided. The first and second coils are connected so that the winding directions of the first and second coils are opposite. The second capacitor is connected in parallel to a series circuit of the first coil and the second coil. The first capacitor is connected between a position where the first coil is connected to the second coil and a reference potential electrode. Mutual inductance caused by coupling between the first and second coils and the first capacitor provides a first attenuation pole and a parallel connection circuit of the series circuit and the second capacitor provides a second attenuation pole.